Answer:
The Persian Empire was weakened through weak kings.
Step-by-step explanation:
During Xerxes reign as king, he was known to be hot tempered; however, not in combat. He lost many battles which weakened the Persian Empire little by little. Soon after, King Darius III runs the empire but loses three battles to Alexander the Great. Alexander the Great did preserve the government of the Persian Empire till his death in 323 B.C. Although, King Darius's defeat would mean that the Persian Empire would end.